CN115004494A

CN115004494A - Gas insulated switchgear

Info

Publication number: CN115004494A
Application number: CN202080094348.5A
Authority: CN
Inventors: 安部淳一; 钓本崇夫; 江户贵广; 甲斐孝幸; 中村泰规; 森藤英二
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 2020-01-27
Filing date: 2020-01-27
Publication date: 2022-09-02
Also published as: WO2021152646A1; JPWO2021152646A1; EP4099522A4; JP6837607B1; EP4099522A1

Abstract

The gas insulated switchgear (1) of the present application includes, in a sealed container in which an insulating gas is sealed: a fixed-side electrode (11); and a movable-side electrode (12), the movable-side electrode (12) being driven by a drive mechanism installed in the sealed container and being connected to and separated from the fixed-side electrode (11), the gas-insulated switchgear (1) comprising: a first magnetic body provided inside the outer periphery of the fixed-side electrode (11); a second magnetic body which is cylindrical and surrounds the fixed-side electrode (11); and a current-carrying terminal (15), wherein the current-carrying terminal (15) is provided on the outer periphery of the movable-side electrode (12), and at least one of the first magnetic body and the second magnetic body is a magnet magnetized in the movable direction of the movable-side electrode (12).

Description

Gas insulated switchgear

Technical Field

The present application relates to a gas insulated switchgear.

Background

The following techniques are disclosed: when two points of a stopped power transmission line are grounded, a closed loop is formed, and therefore, magnetic fluxes caused by a healthy phase of the same circuit and a current of another healthy circuit are interlinked, and an electromagnetic induction current flows (for example, see non-patent document 1). As the responsibility and obligation of a switching device provided in an electric power distribution system to connect and disconnect an electric circuit, it is necessary to cut off an electromagnetic induction current flowing therethrough. For example, Japanese institute of Electrical and electronics Engineers Electrical Specification JEC2310 shows that the recovery voltage is 1kV and the switching current is 200A at a rated voltage of 72-120 kV at a current of 1200A.

When the rated voltage is several kV or more, the switchgear is installed inside a pressure tank in which an insulating gas is sealed in order to improve the insulating performance such as creepage. As the insulating gas, SF having excellent insulating properties has been mainly used in the past ₆ A gas. However, since the SF6 gas is a greenhouse gas having a very high global warming potential, its emission into the atmosphere is now limited, and instead of the SF6 gas, it is desirable to use dry air or CO as an insulating gas having a low global warming potential ₂ 、N ₂ And the like. SF with higher breaking performance when insulating gas is used ₆ In the case of gas, the breaking of the electromagnetically induced current can be performed by a so-called tangential method. The pinch method is a method of interrupting current by extending an arc generated when the electrodes are separated by a driving device. But with SF ₆ In contrast to the gas, dry air having a breaking performance of only about 1/100 has a problem that breaking by the flat cutting method is difficult.

In order to solve the above problem, for example, a method is disclosed in which a magnet is provided inside a switchgear, and an arc generated when a current is interrupted is rotated to interrupt the current (see, for example, patent document 1). The rotation of the arc when using magnets is caused by electromagnetic forces between the current flowing in the arc and the magnetic field that travels straight with the arc. In addition, in order to improve the arc interruption performance, a magnetic body is provided in the vicinity of the magnet for the purpose of strengthening the magnetic field generated by the magnet.

Documents of the prior art

Patent literature

Patent document 1: japanese patent application laid-open No. 2010-251056

Non-patent document

Non-patent document 1: "high-current disconnection of isolator and grounding device in gas-insulated switchgear", journal of the institute of Electrical and electronics treatise B (journal of the Power and energy sector), Vol.112, No.11, p987-996, 1992

Disclosure of Invention

Technical problem to be solved by the invention

In the configuration of the switching device in patent document 1, since the annular magnetic body having the inner diameter larger than the permanent magnet and the outer diameter smaller than the permanent magnet is disposed coaxially with the permanent magnet on the upper surface of the annular permanent magnet, the magnetic body deforms the magnetic field generated from the permanent magnet, and the magnetic field in the radial direction on the fixed electrode can be enhanced. However, when the permanent magnet and the magnetic body are disposed close to each other, an arc generated when the current is interrupted moves to the vicinity of the outer periphery of the movable-side electrode due to an increased magnetic field, and there is a problem that a component disposed on the outer periphery of the movable-side electrode such as the energizing terminal is damaged.

The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a gas-insulated switchgear in which damage to a current-carrying terminal provided on the outer periphery of a movable-side electrode due to an arc is suppressed.

Means for solving the problems

The gas-insulated switchgear disclosed in the present application includes, in a sealed container in which an insulating gas is sealed: a fixed-side electrode; and a movable-side electrode driven by a driving mechanism installed in the hermetic container and connected to and separated from the fixed-side electrode, the gas-insulated switchgear including: a first magnetic body provided inside an outer periphery of the fixed-side electrode; a second magnetic body which is cylindrical and surrounds the fixed-side electrode; and an energizing terminal provided on an outer periphery of the movable-side electrode, at least one of the first magnetic body and the second magnetic body being a magnet magnetized in a movable direction of the movable-side electrode.

Effects of the invention

According to the gas-insulated switchgear disclosed in the present application, it is possible to suppress damage to the current-carrying terminal provided on the outer periphery of the movable-side electrode due to arcing.

Drawings

Fig. 1 is a schematic configuration diagram showing the inside of a gas insulated switchgear according to embodiment 1.

Fig. 2 is an enlarged cross-sectional view of a main part of the gas insulated switchgear according to embodiment 1.

Fig. 3 is an enlarged cross-sectional view of a main part of the gas insulated switchgear according to embodiment 1.

Fig. 4 is an enlarged cross-sectional view of a main part of the gas insulated switchgear according to embodiment 1.

Fig. 5 is a diagram illustrating arc rotation of the gas insulated switchgear according to embodiment 1.

Fig. 6 is a diagram illustrating arc rotation of the gas insulated switchgear according to embodiment 1.

Fig. 7 is a diagram illustrating arc rotation of the gas insulated switchgear according to embodiment 1.

Fig. 8 is a diagram for explaining the influence of an arc in the gas insulated switchgear according to embodiment 1.

Fig. 9 is a diagram showing the distribution of magnetic field when a rectangular permanent magnet is used.

Fig. 10 is an enlarged cross-sectional view of a main part of the gas insulated switchgear according to embodiment 1.

Fig. 11 is an enlarged cross-sectional view of a main part of a gas insulated switchgear according to embodiment 2.

Fig. 12 is an enlarged cross-sectional view of a main part of a gas insulated switchgear according to embodiment 3.

Fig. 13 is an enlarged cross-sectional view of a main part of a gas insulated switchgear according to embodiment 4.

Fig. 14 is a diagram for explaining the influence of an arc in the gas insulated switchgear according to embodiment 4.

Detailed Description

Hereinafter, a gas insulated switchgear according to an embodiment will be described with reference to the drawings. In addition, the same or corresponding members and portions are denoted by the same reference numerals in the drawings.

Embodiment 1.

Fig. 1 is a schematic configuration diagram showing the inside of a gas insulated switchgear 1. In the gas insulated switchgear 1,

pressure tanks

4a and 4b as sealed vessels are adjacently provided inside a compartment 6 as a metal case. In the inner spaces of the

pressure tanks

4a and 4b, for example, dry air and CO are sealed at a high pressure of about 0.5MPa to 0.7MPa under an absolute pressure ₂ 、N ₂ Such an insulating gas having a low global warming potential. The gas-insulated switchgear 1 has the following structure: the current introduced from the cable 7 is drawn out to a bus bar 9 connected to the upper portion inside the pressure tank 4a via the vacuum circuit breaker 2 and the isolator 3. The vacuum circuit breaker 2 and the isolator 3 are connected to the inside of the pressure tank 4b via a main circuit conductor 8. For the switches of the vacuum circuit breaker 2 and the isolator 3, the driving device 5 which is mounted to the outside of the pressure tank 4b via the tank wall 10 and has a driving mechanism is used. The isolator 3 is a device for breaking a main circuit, and is connected to the vacuum circuit breaker 2 and other devices, for example, through a conductor made of a copper plate. In addition, if the driving mechanism is mounted on the hermetic container, the mounting position may be the outside or the inside of the hermetic container.

The structure of the separator 3, which is an essential part of the present application, will be described. Fig. 2 to 4 are enlarged sectional views of a main part of the separator 3 of the gas insulated switchgear 1 according to embodiment 1. Fig. 2 is a sectional view of the separator 3 when the separator is opened, fig. 3 is a sectional view of the separator 3 when the separator is closed, and fig. 4 is a sectional view of the separator during opening of the current path. As shown in fig. 2, the separator 3 is constituted by a fixed-side electrode 11 and a movable-side electrode 12, which are provided so as to be able to be connected and separated to open an electric circuit, and an arc shield 16 surrounding these electrodes, respectively. The fixed-side electrode 11 is provided in a cylindrical shape, for example, and extends in the movable direction of the movable-side electrode 12. In fig. 2 to 4, the left-right direction is the movable direction of the movable-side electrode 12. The movable-side electrode 12 is driven by a movable-side electrode rod (not shown) connected to the driving device 5 shown in fig. 1. The movable-side electrode 12 is movable so as to be connected to and separated from the fixed-side electrode 11. The movable-side electrode 12 is provided in a cylindrical shape, for example, and extends in the movable direction. The arc shield 16 is a member for relaxing the electric field of the fixed-side electrode 11 and the movable-side electrode 12 and protecting the fixed-side electrode 11 and the movable-side electrode 12 from damage due to an arc. Further, the arc shield 16 suppresses the adhesion of the melt caused by the arc to the fixed-side electrode 11 and the movable-side electrode 12. The fixed-side arc shield 16a is provided on the fixed-side electrode 11, and the movable-side arc shield 16b is provided on the movable-side electrode 12.

Inside the outer periphery of the movable-side electrode 12, a permanent magnet 13 as a first magnetic body in a cylindrical shape is provided in a cavity portion 12a in the center of the movable-side electrode 12. The permanent magnet 13 is magnetized in the movable direction of the movable-side electrode 12, and the side opposite to the fixed-side electrode 11 is an N-pole, for example. The permanent magnet 13 is, for example, a neodymium magnet, a samarium cobalt magnet, and a ferrite magnet, but is not limited to these. Here, the permanent magnet 13 is disposed at a position where the end face of the movable-side electrode 12 and the end face of the permanent magnet 13 coincide, but the position at which the permanent magnet 13 is disposed is not limited to this. The end face of the movable-side electrode 12 and the end face of the permanent magnet 13 may be made not to coincide, the cavity portion 12a of the movable-side electrode 12 may be formed deep, and the permanent magnet 13 may be disposed on the inner side of the movable-side electrode 12. This is to suppress the influence of heat caused by the arc. By suppressing the influence of heat, the thermal magnetization of the permanent magnet 13 can be suppressed.

A magnetic body 14, which is a second magnetic body having a cylindrical shape, is disposed on a circle concentric with the permanent magnet 13, and surrounds the movable-side electrode 12, and is provided on the movable-side arc shield 16 b. The magnetic body 14 is a ferromagnetic body such as iron or an alloy containing iron having a high magnetic permeability. Since the permanent magnet 13 is cylindrical in shape and the magnetic body 14 disposed on a circle concentric with the permanent magnet 13 is cylindrical in shape, the distance between the permanent magnet 13 and the magnetic body 14 is equal from any position of the outer peripheral side surface of the permanent magnet 13. Therefore, a uniform magnetic field is formed between the permanent magnet 13 and the magnetic body 14. Here, the magnetic body 14 is provided inside the movable arc shield 16b, but the position of the magnetic body 14 is not limited thereto, and the magnetic body 14 may be provided on the outer peripheral side of the movable arc shield 16 b.

The current-carrying terminal 15 is provided on the outer periphery of the movable electrode 12. The energization terminal 15 is a terminal which is connected to an energization portion (not shown) as an energization path connected to other equipment and through which a current flows between the movable-side electrode 12 and the energization portion. The current-carrying terminal 15 is formed of, for example, a spring member capable of carrying current. The member provided on the outer periphery of the movable-side electrode 12 is not limited to the energizing terminal 15, and may be another member. The position of the movable-side electrode 12 at which the energizing terminal 15 is provided is not limited to the side connected to and separated from the fixed-side electrode 11.

The movable-side electrode 12 is driven in the left-right direction in fig. 2 to 4 by the driving device 5 shown in fig. 1. As shown in fig. 3, by driving the movable-side electrode 12 in the right direction, the movable-side electrode 12 and the fixed-side electrode 11 are closed. When the movable-side electrode 12 is driven leftward from the closed state, the movable-side electrode 12 and the fixed-side electrode 11 are opened. As shown in fig. 4, when the movable-side electrode 12 and the fixed-side electrode 11 are energized at the time of opening the electrodes, an arc 17 is generated between these electrodes.

The rotation of the arc 17 will be explained. Fig. 5 to 7 are diagrams illustrating rotation of the arc 17 in the gas insulated switchgear 1 according to embodiment 1, and fig. 5 is a cross-sectional view of the dashed line in fig. 4 viewed from the direction of the arrow a. Fig. 6 and 7 are perspective views schematically showing a state where the arc 17 generated at the time of opening the poles reaches rotation. In fig. 5, the movable arc shield and the current-carrying terminal are omitted. The magnetic field is uniformly distributed between the permanent magnet 13 and the magnetic body 14 as shown by the magnetic field direction 18 in fig. 5. When the arc 17 is generated by opening the electrode, the current flows in the direction of the arrow, mainly with a component in the direction perpendicular to the electrode, as shown in fig. 6, when no magnetic field is applied to the arc 17. When the magnetic field from the permanent magnet 13 is applied to the arc 17, as shown in fig. 7, the lorentz force 19 acts on the current in the direction perpendicular to the magnetic field direction 18, and therefore the arc 17 starts to rotate on the movable-side electrode 12. As shown in fig. 5, the lorentz force 19 acts in a direction rotating with respect to the center of the permanent magnet 13. As the arc 17 rotates by the lorentz force 19, the direction of the current is bent as shown in fig. 7, and the current flows so as to change from the direction perpendicular to the electrodes to the horizontal direction.

The influence of the arc 17 on the energizing terminal 15 will be described. Fig. 8 is a diagram for explaining the influence of the arc 17 of the gas insulated switchgear 1 in embodiment 1. In the figure, a magnetic field direction 18a shown by a dotted line is a magnetic field direction when the magnetic body 14 is not provided, and a magnetic field direction 18 shown by a solid line is a magnetic field direction in the present embodiment where the magnetic body 14 is provided. When the magnetic body 14 is not provided, a strong magnetic field is formed near the permanent magnet 13, that is, at a position close to the energizing terminal 15. In the magnetic field direction 18a, the arc 17 rotates at a position close to the energizing terminal 15. When the arc 17 rotates, the lorentz force 19 acts in the direction of the energizing terminal 15 when the current of the arc 17 is mainly a component flowing in the direction perpendicular to the paper surface. Therefore, the arc 17 may be turned or brought into contact with the current-carrying terminal 15. When the arc 17 comes into contact with the energizing terminal 15, the energizing terminal 15 may melt and burn. Even when the current-carrying terminal 15 is not melted, the melt generated by the arc 17 may contact the current-carrying terminal 15, and the current-carrying performance of the current-carrying terminal 15 may be lowered.

When the magnetic body 14 is provided, a strong magnetic field is formed not in the vicinity of the permanent magnet 13 but in a direction from the permanent magnet 13 toward the outer periphery of the separator 3 where the magnetic body 14 is provided. In the magnetic field direction 18, the arc 17 rotates at a position between the permanent magnet 13 and the magnetic body 14 close to the magnetic body 14, that is, at a position apart from the energizing terminal 15 in the direction of the outer periphery of the isolator 3. Therefore, when the arc 17 rotates in the magnetic field direction 18, the lorentz force 19 does not act in the direction of the energizing terminal 15 when the current of the arc 17 is mainly a component flowing in the direction perpendicular to the paper surface. Therefore, damage of the energizing terminal 15 due to the arc 17 is suppressed. Further, since a uniform magnetic field is formed between the permanent magnet 13 and the magnetic body 14, the lorentz force 19 does not act in the direction of the energizing terminal 15, and damage of the energizing terminal 15 by the arc 17 is suppressed. Fig. 9 is a view showing the magnetic field distribution when the permanent magnet 13 is not cylindrical but, for example, rectangular in shape, in the same sectional view as fig. 5. When permanent magnet 13 is rectangular, a uniform magnetic field is not formed between permanent magnet 13 and magnetic body 14 because the distance between permanent magnet 13 and magnetic body 14 is not equal. A magnetic field in a magnetic field direction 18 shown in fig. 8 is formed at a portion where the distance between the permanent magnet 13 and the magnetic body 14 is short, and a magnetic field in a magnetic field direction 18a shown in fig. 8 is formed at a portion where the distance between the permanent magnet 13 and the magnetic body 14 is long. Although a uniform magnetic field is not formed between permanent magnet 13 and magnetic body 14, since there is a position where a magnetic field is formed in a magnetic field direction 18 as shown in fig. 8, damage of energizing terminal 15 due to arc 17 is suppressed. In order to more effectively suppress damage to the energization terminals 15, it is desirable that the cylindrical permanent magnets 13 and the cylindrical magnetic bodies 14 are arranged on concentric circles, and a uniform magnetic field is formed between the permanent magnets 13 and the magnetic bodies 14. However, the shape of the permanent magnet 13 is not limited to the cylindrical shape, and may be a rectangle or a polygonal column. The shape of the magnetic body 14 is not limited to a cylindrical shape, and may be a cylindrical shape whose outer periphery is formed in a polygonal shape. The arrangement of the permanent magnets 13 and the magnetic bodies 14 is not limited to concentric circles.

As described above, the columnar magnetic body 14 having no cutting position is provided, but the shape of the magnetic body 14 is not limited thereto. Fig. 10 is a cross-sectional view seen from the direction of arrow a in the one-dot chain line of fig. 4. The magnetic body 14 as the second magnetic body is configured to be cut in the movable direction of the movable-side electrode 12 at least one position and provided with a gap, and here, the magnetic body 14 is configured to be divided into two parts. The magnetic body 14 is divided into a magnetic body 14a and a magnetic body 14b with a gap of about several mm, for example. By providing the gap, magnetic saturation of the magnetic body 14 can be suppressed when a large current is applied. By suppressing magnetic saturation, a magnetic field is maintained between the permanent magnet 13 and the magnetic body 14.

As described above, in the gas insulated switchgear 1, since the cylindrical magnetic body 14 is provided so as to surround the movable side electrode 12 including the permanent magnet 13, the lorentz force 19 does not act in the direction of the energizing terminal 15, which is a member provided on the outer periphery of the movable side electrode 12, and damage to the energizing terminal 15 due to the arc 17 can be suppressed. Further, in the case where the permanent magnet 13 is cylindrical and the magnetic body 14 provided on a circle concentric with the permanent magnet 13 is cylindrical, since a uniform magnetic field is formed between the permanent magnet 13 and the magnetic body 14, the lorentz force 19 does not act in the direction of the energizing terminal 15, and damage to the energizing terminal 15 due to the arc 17 can be more effectively suppressed. Further, since the lorentz force 19 does not act in the direction of the outer periphery of the movable side electrode 12, the energization terminal 15 can be provided on the outer periphery of the movable side electrode 12 on the side of being connected to and separated from the fixed side electrode 11. In addition, the magnetic body 14 is cut in the movable direction of the movable-side electrode 12 at least one position and provided with a gap, and at this time, magnetic saturation of the magnetic body 14 can be suppressed.

Embodiment 2.

A gas-insulated switchgear apparatus 1 according to embodiment 2 will be described. Fig. 11 is an enlarged cross-sectional view of a main part of the separator 3 of the gas insulated switchgear 1. The isolator 3 of the gas insulated switchgear 1 according to embodiment 2 is configured such that a permanent magnet 20 having a magnetization direction opposite to that of the permanent magnet 13 is provided in the movable-side arc shield 16b, instead of the magnetic body 14 provided in embodiment 1.

Inside the outer periphery of the movable-side electrode 12, a permanent magnet 13 as a first magnetic body of a cylindrical shape is provided in a cavity portion 12a in the center of the movable-side electrode 12. The permanent magnet 13 is magnetized in the movable direction of the movable-side electrode 12, and the side opposite to the fixed-side electrode 11 is an N-pole, for example. The permanent magnet 20, which is a second magnetic body having a cylindrical shape, is disposed on a circle concentric with the permanent magnet 13 and is provided on the movable-side arc shield 16b so as to surround the movable-side electrode 12. The permanent magnet 20 is magnetized in the movable direction of the movable-side electrode 12 so that the magnetization direction becomes the opposite direction to the permanent magnet 13, for example, the side opposite to the fixed-side electrode 11 is the S pole. The permanent magnet 20 is, for example, a neodymium magnet, a samarium cobalt magnet, and a ferrite magnet, but is not limited to these.

Since the second magnetic body is used as the permanent magnet 20 instead of the magnetic body 14, the value of the magnetic flux density of the magnetic field formed between the permanent magnet 13 and the permanent magnet 20 becomes higher than that in the case of embodiment 1. Therefore, the force acting on the arc generated at the time of the disconnection also becomes strong, the arc is easily disconnected, the possibility of the arc coming into contact with the energization terminal 15 is further reduced, and the breakage of the energization terminal 15 due to the arc can be further suppressed. Since the value of the magnetic flux density of the magnetic field formed between the

permanent magnets

13 and 20 becomes high and the magnetic flux in the magnetic field direction 18a shown in fig. 8 relatively decreases, the breakage of the energizing terminal 15 due to the arc can be further suppressed.

As described above, in the gas insulated switchgear 1, since the permanent magnet 20 having the opposite magnetization direction to the permanent magnet 13 is provided in the movable-side arc shield 16b, the value of the magnetic flux density of the magnetic field formed between the permanent magnet 13 and the permanent magnet 20 becomes high, the force acting on the arc generated at the time of disconnection becomes strong, and the damage of the current-carrying terminal 15 due to the arc can be further suppressed.

Embodiment 3.

A gas-insulated switchgear 1 according to embodiment 3 will be described. Fig. 12 is an enlarged cross-sectional view of a main part of the separator 3 of the gas insulated switchgear 1. The separator 3 of the gas insulated switchgear 1 according to embodiment 2 is configured such that a magnet 21 is provided on the movable-side electrode 12, instead of the permanent magnet 13 provided in embodiment 2.

Inside the outer periphery of the movable-side electrode 12, a permanent magnet 21, which is a first magnetic body in a cylindrical shape, is provided in a cavity portion 12a in the center of the movable-side electrode 12. The magnetic body 21 is a ferromagnetic body such as iron or an alloy containing iron having a high magnetic permeability. The permanent magnet 20, which is a second magnetic member having a cylindrical shape, is disposed on a circle concentric with the magnet 21 and is provided on the movable-side arc shield 16b so as to surround the movable-side electrode 12. The permanent magnet 20 is magnetized in the movable direction of the movable-side electrode 12, and the side opposite to the fixed-side electrode 11 is the S-pole, for example. The permanent magnet 20 is, for example, a neodymium magnet, a samarium cobalt magnet, and a ferrite magnet, but is not limited to these.

By using the permanent magnet 20 as the second magnetic body, the value of the magnetic flux density of the magnetic field formed between the magnet 21 and the permanent magnet 20 is increased as compared with the case of embodiment 1, and therefore, the force acting on the arc generated at the time of disconnection is also increased, the arc is easily disconnected, the possibility that the arc comes into contact with the energizing terminal 15 can be further reduced, and the breakage of the energizing terminal 15 due to the arc can be further suppressed. The reason why the value of the magnetic flux density becomes larger than that in embodiment 1 is that the volume of the permanent magnet 20 is larger than that of the permanent magnet 13. Further, since the permanent magnet is not provided on the movable-side electrode 12 to which current is applied, and the permanent magnet 20 is provided on the movable-side arc shield 16b distant from the movable-side electrode 12, the permanent magnet 20 is not affected by demagnetization caused by heat generated by current application. Therefore, the reliability of the gas insulated switchgear 1 is improved.

As described above, in the gas insulated switchgear 1, since the value of the magnetic flux density of the magnetic field formed between the magnet 21 and the permanent magnet 20 is increased by using the first magnetic body as the magnet 21 and the second magnetic body as the permanent magnet 20 as compared with embodiment 1, the force acting on the arc generated at the time of disconnection is increased, and the damage of the current-carrying terminal 15 due to the arc can be further suppressed. Further, since the permanent magnet 20 is provided on the movable-side arc shield 16b away from the movable-side electrode 12, demagnetization of the permanent magnet 20 due to heat generated by energization can be suppressed.

Embodiment 4.

A gas-insulated switchgear 1 according to embodiment 4 will be described. Fig. 13 is an enlarged cross-sectional view of a main part of the separator 3 of the gas insulated switchgear 1. The isolator 3 of the gas insulated switchgear 1 according to embodiment 4 is configured such that the permanent magnet 13, which is a first magnetic body, is provided on the fixed-side electrode 11, and the magnetic body 14, which is a second magnetic body, is provided on the fixed-side arc shield 16 a.

A first magnetic body 13 in a cylindrical shape, i.e., a permanent magnet, is provided in a cavity portion 11a in the center of the fixed-side electrode 11 inside the outer periphery of the fixed-side electrode 11. The permanent magnet 13 is magnetized in the movable direction of the movable-side electrode 12, and the side opposite to the movable-side electrode 12 is an N-pole, for example. The permanent magnets 13 are, for example, but not limited to, neodymium magnets, samarium-cobalt magnets, and ferrite magnets. A magnetic body 14, which is a second magnetic body having a cylindrical shape, is arranged on a circle concentric with the permanent magnet 13 and is provided on the fixed-side arc shield 16a so as to surround the fixed-side electrode 11. The magnetic body 14 is a ferromagnetic body such as iron or an alloy containing iron having a high magnetic permeability. Since the permanent magnet 13 is cylindrical in shape and the magnetic body 14 disposed on a circle concentric with the permanent magnet 13 is cylindrical in shape, the distance between the permanent magnet 13 and the magnetic body 14 is equal from any position of the outer peripheral side surface of the permanent magnet 13. Therefore, a uniform magnetic field is formed between the permanent magnet 13 and the magnetic body 14.

The influence of the arc 17 on the energizing terminal 15 will be described. Fig. 14 is a diagram for explaining the influence of the arc 17 of the gas insulated switchgear 1 in embodiment 4. In the figure, the magnetic field direction 18a shown by the broken line is the magnetic field direction when the magnetic body 14 is not provided, and the magnetic field direction 18 shown by the solid line is the magnetic field direction in the present embodiment where the magnetic body 14 is provided. When the magnetic body 14 is not provided, a strong magnetic field is formed near the permanent magnet 13. In the magnetic field direction 18a, the arc 17 rotates at a position close to the permanent magnet 13. When the arc 17 rotates, the lorentz force 19 acts in the direction of the energizing terminal 15 when the current of the arc 17 is mainly a component flowing in the direction perpendicular to the paper surface. Therefore, the arc 17 may be turned or brought into contact with the current-carrying terminal 15. When the arc 17 comes into contact with the energizing terminal 15, the energizing terminal 15 may melt and burn. Even when the current-carrying terminal 15 is not melted, the melt generated by the arc 17 may contact the current-carrying terminal 15, and the current-carrying performance of the current-carrying terminal 15 may be lowered.

When the magnetic body 14 is provided, a strong magnetic field is formed not in the vicinity of the permanent magnet 13 but in a direction from the permanent magnet 13 toward the outer periphery of the separator 3 where the magnetic body 14 is provided. In the magnetic field direction 18, the arc 17 rotates at a position between the permanent magnet 13 and the magnetic body 14 close to the magnetic body 14, that is, at a position distant from the energizing terminal 15 in the direction of the outer periphery of the isolator 3. Therefore, when the arc 17 rotates in the magnetic field direction 18, the lorentz force 19 does not act in the direction of the energizing terminal 15 when the current of the arc 17 is mainly a component flowing in the direction perpendicular to the paper surface. Therefore, damage of the energizing terminal 15 due to the arc 17 is suppressed. Further, since a uniform magnetic field is formed between the permanent magnet 13 and the magnetic body 14, the lorentz force 19 does not act in the direction of the energizing terminal 15, and damage of the energizing terminal 15 by the arc 17 is suppressed. Further, since a strong magnetic field is formed on the fixed-side electrode 11 side, the arc 17 is likely to rotate at a position close to the fixed-side electrode 11. Therefore, the damage of the current-carrying terminal 15 of the movable electrode 12 due to the arc 17 is further suppressed.

As described above, the permanent magnet 13 as the first magnetic body is provided on the fixed-side electrode 11, and the magnetic body 14 as the second magnetic body is provided on the fixed-side arc shield 16a, but the configurations of the first magnetic body and the second magnetic body are not limited thereto. The first magnetic body may be a permanent magnet 13, and the second magnetic body may be a permanent magnet having a magnetization direction opposite to that of the permanent magnet 13. The first magnetic body may be a ferromagnetic body, and the second magnetic body may be a permanent magnet magnetized in the movable direction of the movable-side electrode 12.

As described above, in the gas insulated switchgear 1, since the cylindrical magnetic body 14 is provided around the fixed-side electrode 11 including the permanent magnet 13, the lorentz force 19 does not act in the direction of the energizing terminal 15, which is a member provided on the outer periphery of the movable-side electrode 12, and damage to the energizing terminal 15 due to the arc 17 can be suppressed. Further, in the case where the permanent magnet 13 is cylindrical and the magnetic body 14 provided on a circle concentric with the permanent magnet 13 is cylindrical, since a uniform magnetic field is formed between the permanent magnet 13 and the magnetic body 14, the lorentz force 19 does not act in the direction of the energizing terminal 15, and damage to the energizing terminal 15 due to the arc 17 can be more effectively suppressed. Further, by providing the permanent magnet 13 and the magnetic body 14 on the side of the fixed-side electrode 11, a strong magnetic field is formed on the side of the fixed-side electrode 11, and the arc 17 is likely to rotate at a position close to the fixed-side electrode 11, so that damage to the energizing terminal 15 provided on the movable-side electrode 12 due to the arc 17 can be further suppressed.

Although various exemplary embodiments and examples have been described in the present application, the various features, modes, and functions described in 1 or more embodiments are not limited to the application to specific embodiments, and may be applied to the embodiments alone or in various combinations.

Therefore, it is considered that numerous modifications not illustrated are also included in the technical scope disclosed in the present specification. For example, the present invention includes a case where at least one of the components is modified, added, or omitted, and a case where at least one of the components is extracted and combined with the components of the other embodiments.

Description of the reference symbols

1 gas insulated switchgear

2 vacuum circuit breaker

3 isolator

4a pressure tank

4b pressure tank

5 drive device

6 partition

7 electric cable

8 main circuit conductor

9 bus

10 case wall

11 fixed side electrode

11a hollow part

12 movable side electrode

12a hollow part

13 permanent magnet

14 magnetic body

15 terminal for electrifying

16 arc shield

16a fixed side arc shield

16b movable side arc shield

17 arc of electric arc

18 direction of magnetic field

18a magnetic field direction

19 Lorentz force

20 permanent magnet

21 a magnetic body.

Claims

1. A gas-insulated switchgear comprising, in a sealed container in which an insulating gas is sealed:

a fixed-side electrode; and

a movable-side electrode driven by a drive mechanism installed in the hermetic container and connected to and disconnected from the fixed-side electrode, the gas-insulated switchgear comprising:

a first magnetic body provided inside an outer periphery of the fixed-side electrode;

a second magnetic body which is cylindrical and surrounds the fixed-side electrode; and

an energizing terminal provided on an outer periphery of the movable-side electrode,

at least one of the first magnetic body and the second magnetic body is a magnet magnetized in a movable direction of the movable-side electrode.

2. A gas-insulated switchgear comprising, in a sealed container in which an insulating gas is sealed:

a fixed-side electrode; and

a first magnetic body provided inside an outer periphery of the movable-side electrode;

a second magnetic body which is cylindrical and surrounds the movable-side electrode; and

3. Gas-insulated switchgear device according to claim 2,

the first magnetic body is cylindrical in shape.

4. Gas insulated switchgear according to any of the claims 1 to 3,

the second magnetic body is cut at least at one place and provided with a gap.

5. Gas insulated switchgear according to any of the claims 1 to 3,

the first magnetic body and the second magnetic body are magnets having opposite magnetization directions.